A member for developing electrostatic latent images to visible images is disclosed, which comprises a support, a first coating layer comprising an elastic material formed on the support, and a second coating layer comprising a flexible resin formed on the first coating layer.
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1. A member for developing electrostatic latent images to visible images, comprising a support, a first coating layer comprising an elastic material formed on said support, and a second coating layer comprising an electroconductive material and a flexible resin having a elongation ratio of 10% to 500% formed on said first coating layer, said flexible resin being a resin prepared by cross-linking a fluorine-containing polymer comprising a fluoro-olefin and a hydroxyl-group containing vinyl ether through a polyfunctional isocyanante isocyanate, wherein said first and second coating layers have a volume resistivity of 106 to 1011 Ω-cm, and wherein said elastic material of said first coating layer comprises as a base material a material selected from the group consisting of nitrile rubber, epichlorohydrin rubber, urethane rubber, silicone rubber, and mixtures thereof.
2. The member for developing electrostatic latent images as claimed in
3. The member for developing electrostatic latent images as claimed in
4. The member for developing electrostatic latent images as claimed in
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2.0 × 1011
As shown in Table 6, the characteristics of the development rollers according to the present invention are improved in comparison with the comparative development roller.
In addition to the above-described examples, when an NBR-type first coating layer and a second coating layer, with the volume resistivities thereof being close to each other, are used in combination, the advantages of the present invention are available.
A carbon-containing silicone rubber layer was formed on an SUS core having a diameter of 16 mm by press-molding with a mixture of the following components cured under the following curing conditions:
TBL Parts by Weight Silicone rubber compound 100 (Trademark "SH831U" made by Toray Industries, Inc.) Carbon black (Trademark 3.5 "Ketschen Black EC Carbon" made by AKZO chemie) Vulcanizing agent (Trademark 1 "RC-4" made by Toray Industries, Inc.) Curing Conditions First vulcanizing 170°C/10 min. (Press molding) Second vulcanizing 200°C/4 hrs.After the completion of the curing, the coating layer was subjected to surface grinding, whereby a comparative development roller 1-2 with a diameter of 20 mm was prepared.
A primer (Trademark "Toray Silicone DY39-020" made by Toray Industries, Inc.) was applied to the same carbon-containing silicone rubber layer as employed in Comparative Example 1-2 and then air-dried for 1 hour. On this layer, an addition-type silicon resin (Trademark "DC1-2577" made by Toray Industries, Inc.) was coated by spray coating and cured at 150°C for 1 hour. The thus formed resin layer was subjected to successive surface grindings with Imprial Wrapping Films #320 and #600 (made by Sumitomo 3M Limited.), whereby a development roller 1-4 having a silicone resin layer with a thickness of 50 μm according to the present invention was prepared.
Polyester (Trademark "ODX-106" made by Dainippon Ink and Chemicals, Inc.) was dehydrated at 120°C for 30 minutes under reduced pressure. To 100 parts by weight of the dehydrated polyester, 11 parts by weight of isocyanate (Trademark "Millionate MT" made by Nippon Polyurethane Industry Co., Ltd.) were added. This mixture was poured into a mold in which an SUS-made core with a diameter of 16 mm was placed, and then cured at 100°C for 3 hours, whereby a development roller was prepared.
After the completion of the curing, the thus prepared development roller was subjected to surface grinding, whereby a comparative development roller 1-3 having a diameter of 20 mm was prepared.
Example 1-4 was repeated except that a potassium titanate fiber (Trademark "TISMO" made by Otsuka Chemical Co., Ltd.) was dispersed as a reinforcing material in the addition-type silicon resin employed in Example 1-4, at a ratio of 20 parts by weight to 100 parts by weight of the solid content of the resin, whereby a development roller 1-5 according to the present invention was prepared.
A fluorine-type copolymer resin (Trademark "Lumifron 610C" made by Asahi Glass Co., Ltd.) was coated onto the same development roller as employed in Comparative Example 1-3 by spray coating, and cured at 150°C for 30 minutes. The thus obtained resin layer was subjected to surface grinding by the same method as employed in Example 1-4, whereby a development roller 1-6 having a fluoroplastic resin layer with a thickness of 50 μm according to the present invention was prepared.
An acrylic urethane resin (Trademark "Urethane Top #8500" made by Asia Industry Co., Ltd.) was coated onto the same development roller as employed in Comparative Example 1-3 by spray coating, and cured at 100°C for 30 minutes. The thus obtained resin layer was subjected to surface grinding by the same method as employed in Example 1-4, whereby a development roller 1-7 having an acrylic urethane resin layer with a thickness of 50 μm according to the present invention was prepared.
The results of the evaluation with respect to the above-mentioned characteristics (a) to (d) of the development rollers are shown in Table 7.
| TABLE 7 |
| Characteristics |
| Charge Quantity of |
| Toner (μc/g) Toner Coeffi- |
| Development Positive Negative Releas- Abrasion cient of |
| Roller Toner Toner ability (μm) Friction |
| Comparative +6.5 -3.2 2 12.7 0.82 |
| Example 1-2 (Ad- |
| hered) |
| Example 1-4 +11.5 -6.8 1 3.1 0.32 |
| Example 1-5 +10.8 -5.1 1 1.9 0.23 |
| Comparative +5.1 -4.6 4 5.3 0.78 |
| Example 1-3 |
| Example 1-6 +9.2 -7.5 1 1 or less 0.16 |
| Example 1-7 +10.8 -8.6 1 1 or less 0.25 |
In addition to the previously mentioned first coating layers, the following first coating layers were prepared.
The peripheral surface of an electroconductive core having a diameter of 15 mm was subjected to degreasing, and a vulcanizable adhesive (Trademark "Kemlock 205" made by Road Far East Co., Ltd.) was coated on the surface and dried at room temperature for 30 minutes.
Each composition containing NBR, ECO, or a mixture thereof as a base component as shown in Table 8 was formed into a sheet having a thickness of 1 to 3 mm. This sheet was then wrapped around the adhesive-applied peripheral surface of the previously obtained core until the diameter of roll reached about 32 mm. The thus wrapped rubber sheet was heated and vulcanized at 160°C for 30 minutes with application of a pressure of 100 kg/cm2 in a mold for compression molding.
Thus, an elastic layer comprising NBR, ECO or a mixture thereof as the base component was formed. The thus formed elastic layer was subjected to surface grinding to smoothen the surface thereof, so that development rollers having a diameter of 27 mm including the elastic layer with a thickness of 6 mm were obtained.
The rubber hardness, compression set, volume resistivity and resistance to ozone of the thus prepared rollers are shown in Table 8. The measurements were carried out in the same manner as previously described.
| TABLE 8 |
| Acrylonitrite Fromulation |
| Acrylonitrile |
| Formulation Formulation Formulation Formulation |
| Material Maker (%) 2-1 2-2 |
| 2-3 2-4 |
| Formulation |
| NBR: JSRN250SL Japan 20 100 -- |
| -- 100 |
| Synthetic |
| Rubber |
| Co., Ltd. |
| NBR: JSRN260S Japan 15 -- 100 |
| -- -- |
| Synthetic |
| Rubber |
| Co., Ltd. |
| NBR: NIPOL1312 Japan Zeon 32 30 30 |
| -- 30 |
| Co., Ltd. |
| ECO: Ohsaka -- -- -- |
| 100 100 |
| Epichlomer C Soda Co., |
| Ltd. |
| Softening Agent: Showa -- 10 10 |
| 10 20 |
| Brown factice Chemical |
| Industry |
| Co.,Ltd. |
| Lubricant: -- -- 0.5 0.5 |
| -- 0.5 |
| Stearic Acid |
| Mixing Agent: -- -- -- -- |
| 1 1 |
| Zinc Stearate |
| Vulcanizing -- -- 5 5 |
| 5 10 |
| Promoting Agent: |
| Sulfur |
| Vulcanizing Tsurumi -- 0.25 0.25 |
| 0.25 0.5 |
| Promoting Agent: Kagaku |
| Sulfax H Kogyo |
| K.K. |
| Vulcanizing Sanshin -- 1 1 |
| -- 1 |
| Promoting Agent: Chemical |
| Sanceler TT Industry |
| Co., Ltd. |
| Vulcanizing Sanshin -- 1.5 1.5 |
| -- 1.5 |
| Promoting Agent: Chemical |
| Sanceler DM Industry, |
| Co.,Ltd. |
| Vulcanizing Sanshin 1.0 1.0 |
| -- 1.0 |
| Promoting Agent: Chemical |
| Sanfel R lndustry |
| Co., Ltd. |
| Vulcanizing Sanshin -- -- -- |
| 1.5 1.5 |
| Promoting Agent: Chemical |
| Sanceler 22 Industry |
| Co.,Ltd. |
| Total 149.25 149.25 |
| 117.75 267.0 |
| Vulcanizing Time 30 30 |
| 30 30 |
| 160°C × (minute) |
| Characteristics |
| Rubber Hardness 32 30 |
| 37 34 |
| Permanent 3.1 4.8 |
| 8.6 5.3 |
| Compressive |
| Strain (%) |
| Volume Specific 6 × 103 |
| 109 6 × 1011 4 × 106 1 |
| × 108 |
| Resistance (Ω · |
| cm) |
| Resistance to A2 A2 |
| A1 A1 1 |
| Ozone |
In addition to the previously mentioned second coating layers, the following second coating layers were prepared.
A variety of carbon blacks with different volatile contents are shown in Table 9.
| TABLE 9 |
| Type of Carbon Black Maker Volatile Content |
| (i) Black Pearl #1300 Cabot 9.6 |
| (ii) Black Pearl L " 5.2 |
| (iii) Reagal #660 " 1.0 |
| (iv) Reagel #400 " 2.5 |
| (v) Vulcan XC-72 " 1.7 |
The above volatile contents were measured by extracting each carbon black with toluene and then determining the volatile content at 950°C
Formulations of the carbon black--fluoroplastic at the time of dispersion in a ball mill are shown in Table 10.
| TABLE 10 |
| Formu- Formu- |
| lation lation |
| Composition Maker 3-1 3-2 |
| (i) Various carbon black Cabot 20.0 g 20.0 g |
| in Table 9 |
| (ii) Resin: Lumifron LF-601 Asahi Glass 50.0 g -- |
| Co., Ltd. |
| (iii) Resin: Lumifron LF-651 Asahi Glass -- 50.0 g |
| Co. Ltd. |
| (iv) Solvent: Toluene -- 30.0 g 30.0 g |
| (v) Solvent: Xylene -- 30.0 g 30.0 g |
| Total 130.0 g 130.0 g |
Each of the mixtures with the above-mentioned formulations as shown in Table 10 was dispersed in a ball mill for 10, 20, 40, 60 and 80 hours, respectively to form masterbatches.
Based on each of the thus obtained masterbatches, a resin and a curing agent were added so as to obtain an F/R of 0.10.
The formulations are shown in Table 11.
| TABLE 11 |
| Formulation Formulation |
| Composition Maker 3-1-1 3-2-2 |
| (i) Various Masterbatches -- 10.0 g 10.0 g |
| (ii) Resin: Lumifron LF-601 Asahi Glass Co., Ltd. 20.8 g -- |
| (iii) Resin: Lumifron LF-651 Asahi Glass Co., Ltd. -- 21.8 g |
| (iv) Solvent: Coronate EH Nippon Plyurethane 3.04 g 2.5 g |
| Industry Co., Ltd. |
| (v) Solvent: Toluene/Xylene = -- 60.0 g 64.0 g |
| 1/1 |
| Total 93.84 g 98.3 g |
Basic properties of a fluoroplastic and a curing agent are shown in Table 12.
| TABLE 12 |
| Solid OH value Acid value NCO |
| Content (mg KOH/g (mg KOH/ Content |
| Material (wt. %) polymer) g polymer) (%) |
| (i) Lumifron 50 61 0 -- |
| LF-601 |
| (ii) Lumifron 50 55 6 -- |
| LF-651 |
| (iii) Coronate 100 -- 1 21.3 |
| EH* |
| *Aliphatic isocyanate (Hexamethylene diisocyanate) |
Each carbon black dispersed resin solution shown in Table 11 was coated onto an aluminum-deposited polyester film and cured at 100°C for 2 hours.
The coating was carried out by using the same spray gun as mentioned previously in the same conditions, with a coating thickness of about 30 μm. The volume resistivity was measured with a high-ohmeter (Trademark "4329A-type" made by Yokogawa-Hewlett-Packard, Ltd. after allowing the sample sheet to stand at 20°C and 60% RH for 16 hours. As the cell for measurement, No. 16008A type made by Yokogawa-Hewlett-Packard, Ltd. was used.
With respect to Lumifron LF-601 and Lumifron LF-651, the results are shown in FIGS. 8 and 9, respectively.
As shown in FIGS. 8 and 9, with respect to black carbons having comparatively low volatile contents, and therefore with a small amount of oxygen adsorbed on the surface of carbon black, such as Reagal #660 and Vulcan XC-72, as the dispersion time increases, the dispersion proceeds, so that the electroconductivity thereof is decreased. It is considered that this is because the structure destruction of carbon black will advance in proportion to the dispersion time. In contrast to this, the electroconductivity of the carbon black with a comparatively large volatile content scarcely decrease after a certain period of time even when the dispersion time is extended. Accordingly, the carbon black dispersed resin solution having stable electrical characteristics can be obtained.
As to the Lumifron LF-651 containing carboxyl groups in the resin structure, the volume resistivity is increased in increments of the dispersion property of the carbon black, but the dispersion stability thereof is not changed. Therefore, it is preferably that the volatile content of black carbon suitable for the resin solution for use in the present invention be in the range of 2.5 to 9.6%.
The following carbon black dispersed resin solutions were likewise prepared by using the formulations in Table 13.
| TABLE 13 |
| Formu- Formu- Formu- |
| lation lation lation |
| Composition Maker 4-1 4-2 4-3 |
| Various Carbon black -- 20.0 g 20.0 g 20.0 g |
| in Table 9 |
| Fluoroplastic Asahi 50.0 g -- -- |
| (Lumifron LF-601-C) Glass |
| Co., Ltd. |
| Urethane Resin Hironon -- 100.0 g -- |
| (Ulack C-230U) Chemical |
| Co., Ltd. |
| Silicone Resin Toray -- -- 50.0 g |
| (One-liquid type) Silicone |
| (DCI-2577) Co., Ltd. |
| Toluene -- 25.0 g -- -- |
| Xylene -- 25.0 g -- -- |
| Total 120.0 g 120.0 g 70.0 g |
Each of the mixtures with the above-mentioned formulation as shown in Table 13 were was dispersed in a ball mill for 10, 20, 40, 60 and 80 hours to prepare the respective master batches.
Based on the thus obtained masterbatches with different dispersion times, a resin and a curing agent were added and adjusted to an F/R ratio of 0.10 to form coating compositions.
The formulations of the above-mentioned coating composition are shown in Table 14.
| TABLE 14 |
| Silicon |
| Material Fluoroplastic Urethane resin resin |
| Main ingredient |
| Masterbatch 10.0 g 10.0 g 10.0 g |
| Lumifron LF-601-C 23.6 g -- -- |
| Yulack C-230U -- 28.7 g -- |
| DCI-2577 -- -- 30.2 g |
| (One-liquid type) |
| Hardener |
| Lumifron 601 5.6 g -- -- |
| Hardener |
| Yulack PU-614 -- 11.1 g -- |
| Solvent |
| (a) 60.0 g -- -- |
| (b) -- 15.0 g -- |
| (c) -- -- 60 g |
| Total 99.2 g 64.8 g 100.2 g |
| Solvent Parts by weight |
| (a) Toluene 50.0 |
| Xylene 50.0 |
| (b) Toluene 39.0 |
| Ethyl acetate 17.5 |
| Butyl acetate 17.5 |
| Ethyl cellosolve acetate 17.5 |
| Methyl isobutyl ketone 3.9 |
| Xylene 2.6 |
| Cyclohexane 2.0 |
| (c) Xylene 100.0 |
Each of the carbon black dispersed resin solutions with the above-mentioned F/R ratios were was coated onto an aluminum-deposited polyester film and cured at 100°C For two hours.
The coating was carried out by using the same spray gun as mentioned previously under the same conditions, with a coating thickness of about 30 μm. The volume resistivity was measured with the above Micrometer after allowing the sample sheet to stand at 20°C and 60% RH for 16 hours. As the cell for measurement, No. 16008A type made by Yokogawa-Hewlett-Packard, Ltd, was used.
With respect to a fluoroplastic, an urethane resin and a silicone resin, the results of measurement are shown in FIG. 10, FIG. 11, and FIG. 12, respectively.
As shown in FIGS. 10 through 12, with respect to black carbons having comparatively low volatile contents and therefore with a small amount of oxygen adsorbed on the surface of carbon black, such as Reagal #660 and Vulcan XC-72, as the dispersion time increases, the dispersion proceeds, so that the electroconductivity thereof is decreased. It is considered that this is because the structure destruction of carbon black will advance in proportion to the dispersion time. In contrast to this, the electroconductivity of the carbon black with a comparatively large volatile content scarcely decreases after a certain period of time even when the dispersion time is extended. Accordingly, the carbon black dispersed resin solution having stable electrical characteristics can be obtained.
A Lumifron--Black Pearl L dispersion solution was dispersed in a ball mill for 72 hours to prepare the masterbatch thereof. The formulations were the same as previously mentioned (Formulations 3-1 and 3-2 in Table 10).
Based on the thus obtained masterbatches, a resin and a curing agent were added so as to obtain the following four F/R ratios. The formulations corresponding to the F/R ratios are shown in Tables 15 and 16.
| TABLE 15 |
| F/R Ratio |
| Material 0.05 0.10 0.15 0.20 |
| (i) Masterbatch 10.0 g 10.0 g 10.0 g 100 g |
| (Formulation |
| 3-1 in Table 10) |
| (ii) Resin: Lumifron 45.6 g 20.8 g 12.6 g 8.5 g |
| LF-601 |
| (iii) Hardener: 6.1 g 3.0 g 2.0 g 1.5 g |
| Coronate EH |
| (v) Solvent: 110.0 g 60.0 g 46.0 g 38.0 g |
| Toluene/ |
| Xylene = 1/1 |
| Total 117.7 g 93.8 g 70.6 g 58.0 g |
| TABLE 15 |
| F/R Ratio |
| Material 0.05 0.10 0.15 0.20 |
| (i) Masterbatch 10.0 g 10.0 g 10.0 g 100 g |
| (Formulation |
| 3-1 in Table 10) |
| (ii) Resin: Lumifron 45.6 g 20.8 g 12.6 g 8.5 g |
| LF-601 |
| (iii) Hardener: 6.1 g 3.0 g 2.0 g 1.5 g |
| Coronate EH |
| (v) Solvent: 110.0 g 60.0 g 46.0 g 38.0 g |
| Toluene/ |
| Xylene = 1/1 |
| Total 117.7 g 93.8 g 70.6 g 58.0 g |
Each of the carbon black (Black Pearl L) dispersed resin solutions with the above-mentioned F/R ratios was coated onto an aluminum-deposited polyester film and cured at 100°C for 2 hours.
The method of coating the above solution and the method of measuring the volume resistivity thereof were the same as previously mentioned. The results of measurement are shown in FIGS. 13 and 14.
Further, a fluoroplastic--Black Pearl L dispersed solution was dispersed in a ball mill for 72 hours to prepare the master batch thereof. The formulation is given in the Formulation 4-1 in Table 13.
Based on the thus obtained masterbatches, a resin and a curing agent were added so as to obtain the following five F/R ratios. The formulations corresponding to the F/R ratios are shown in Table 17.
| TABLE 17 |
| F/R Ratio |
| Material 0.07 0.10 0.13 0.16 0.19 |
| Masterbatch 10.0 g 10.0 g 10.0 g 10.0 g 10.0 g |
| Lumifron LF-601-C 35.5 g 23.6 g 17.2 g 13.1 g 10.5 g |
| (Main ingredient) |
| Lumifron LF-601-C 7.9 g 5.6 g 4.3 g 3.5 g 2.9 g |
| (Curing agent) (c) |
| Solvent (d) 90.0 g 60.0 g 45.0 g 35.0 g 25.0 g |
| (c) Trademark of a curing agent for a modified |
| fluoroplastic, made by Asahi Glass Co., Ltd. |
| (d) Solvents Parts by weight |
| Toluene 50.0 |
| Xylene 50.0 |
Each of the carbon black (Black Pearl L) dispersed resin solutions with the above-mentioned F/R ratios was coated onto an aluminum-deposited polyester film and cured at 100°C for 2 hours.
The method of coating the above solution and the method of measuring the volume resistivity thereof are the same as previously mentioned. The results of measurement are shown in FIG. 15.
Further, a silicon resin--Black Pearl L dispersed solution was dispersed in a ball mill for 48 hours to prepare the masterbatch thereof. The formulation is given in the Formulation 4-3 in Table 13.
Based on the thus obtained masterbatches, a resin and a curing agent were added so as to obtain the following four F/R ratios. The formulations corresponding to the F/R ratios are shown in Table 18.
| TABLE 18 |
| F/R Ratio |
| Material 0.08 0.10 0.12 0.14 |
| Masterbatch 10.0 g 10.0 g 10.0 g 10.0 g |
| DCI-2577 40.5 g 30.2 g 24.6 g 20.1 g |
| (One-liquid type) |
| Toluene 80.0 g 60.0 g 50.0 g 40.0 g |
Each of the carbon black (Black Pearl L) dispersed resin solutions with the above-mentioned F/R ratios was coated onto an aluminum-deposited polyester film and cured at 150°C for 20 minutes.
The method of coating the above solution and the method of measuring the volume resistivity thereof are the same as previously mentioned. The results of measurement are shown in FIG. 16.
On a first coating layer made of a mixture of NBR and ECO with the formulation 2-4 shown in Table 8, a second coating layer with the formulation with an F/R ratio of 0.10 shown in Table 15 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 2-1 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
On a first coating layer of a development roller, made of an NBR prepared in accordance with the formulation 2-3 shown in Table 8, a second coating layer with the formulation with an F/R ratio of 0.10 in Table 15 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 2-2 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
On a first coating layer made of an NBR prepared in accordance with the formulation 2--2 shown in Table 8, a second coating layer with the formulation with an F/R ratio of 0.10 in Table 16 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 2-3 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
The charge quantity of toner, toner releasability, abrasion, volume resistivity, and resistance to ozone of the above development rollers 2--1, 2--2, and 2-3 according to the present invention were measured. The results are given in Table 19. With respect to the charge quantity of toner, the development unit as shown in FIG. 17 was employed.
| TABLE 19 |
| Charge |
| Quantity of Toner |
| (μc/g) Coefficient Volume |
| Resistance |
| Positive Negative Toner of Abrasion |
| Resistivity to |
| Example Toner Toner Releasability Friction (μm) (Ω |
| · cm) Ozone |
| Example 2-1 +8.3 -7.3 Lank 1 0.18 1 or less 2.1 × |
| 108 A1 |
| Example 2-2 +11.2 -9.6 Lank 1 0.16 1 or less 6.0 × |
| 108 A1 |
| Example 2-3 +9.6 -7.1 Lank 1 0.14 1 or less 1.6 |
| × 1011 A1 |
A comparative development roller 3-2 having a first coating layer made by an NBR prepared in accordance with the formulation 1-2 shown in Table 1, with the surface thereof ground to a surface roughness of 2 μm, was prepared.
On a first coating layer of a development roller, made of an NBR prepared in accordance with the formulation 1-2 shown in Table 1, a second coating layer with the formulation of a Vulcan XC-72--fluoroplastic with an F/R ratio of 0.10 in Table 14 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a comparative development roller 3-1 having a second coating layer with a thickness of 30 μm was prepared.
On a first coating layer made of an NBR-ECO mixture prepared in accordance with the formulation 1-4 shown in Table 1, a second coating layer with the formulation of a Black Pearl L--fluoroplastic with an F/R ratio of 0.10 in Table 14 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 3-1 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
On a first coating layer made of an NBR-ECO mixture prepared in accordance with the formulation 1-5 shown in Table 1, a second coating layer with the formulation of a Black Pearl L--fluoroplastic with an F/R ratio of 0.13 shown in Table 17 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 3-2 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
On a first coating layer made of an NBR-ECO mixture prepared in accordance with the formulation 1-5 shown in Table 1, a second coating layer with the formulation of a Black Pearl L--urethane resin with an F/R ratio of 0.16 in Table 3 was coated by spray coating, and then cured at 100°C for 2 hours, whereby a development roller 3--3 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
A primer (Trademark "Aron Alpha Primer A" made by Toagosei Chemical Industry Co., Ltd.) was extremely thinly applied to a first coating layer made of an NBR-ECO mixture prepared in accordance with the formulation 1-5 shown in Table 1. On this layer, a second coating layer with the formulation of a Black Pearl L--silicone resin with an F/R ratio of 0.10 in Table 18 was coated by spray coating, and then cured at 150°C for 30 minutes, whereby a development roller 3-4 having a second coating layer with a thickness of 30 μm according to the present invention was prepared.
The characteristics of each development roller are shown in Table 20.
| TABLE 20 |
| Charge |
| Quantity of Toner Volume* |
| Resistance |
| Characteristics (μc/g) Resistivity |
| to |
| Development Positive Negative Toner Abrasion (Ω · |
| cm) Ozone |
| Roller Toner Toner Releasability (μm) Minimum |
| Maximum Surface Both Sides |
| Comparative +6.3 -4.8 3 5.8 2.8 × 109 |
| 3.2 × 109 A2 A2 |
| Examples 3-1 |
| Comparative +6.8 -7.2 1 1.0 1.0 × 109 |
| 8.3 × 1010 A1 A2 |
| Example 3-2 or less |
| Example 3-1 +7.4 -6.2 1 1.0 1.8 × |
| 1010 2.6 × 1011 A1 A2 to A1 |
| or less |
| Example 3-2 +6.5 -5.1 1 1.0 3.1 × 109 |
| 4.2 × 109 A1 A1 |
| or less |
| Example 3-3 +6.3 -4.7 1 1 8.9 × 107 |
| 1.6 × 109 A1 A1 |
| or less |
| Example 3-4 +11.1 -8.2 1 2.1 7.3 × 109 |
| 8.3 × 109 A1 A1 |
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